Protecting fabric



Patented Apr. 9, 1929.

NITED TTS 3,708,519 FATE T F. C

ROBERT A. PHAIR, OF ALLENDALE, NEW JERSEY, ASSIGNOR T0 H. KOHNSTAMM & 00., INC., 01 NEW YORK, N. Y., A CORPORATION OF NEWYORK.

PROTECTING FABRIC.

No Drawing. a

When cotton and other vegetable fabrics are laundered they often come out with holes eaten through the fabrics from causes which it has been diflicult to determine. I have found that in some cases these holes are caused by minute quantities of sulphur compounds in the air in which the fabrics are allowed to dry. This condition is most preva lent in the neighborhood of smelters or of large cities where the consumption of coal or oil for heating or other purposes is considerable. The fabric absorbs sulphur comounds as S0 and S0 from the air, while the fabric is wet. *As it dries in the air the oxygen and the water of the atmosphere convert the absorbed gases into sulphuric acid (H. ,SO,).' In as small a quantity as onetenth of one per cent, this injures the fabric when it comes to be ironed.

The ironing operation concentrates the acid in spots or rings in the fabric. When the dry fabric is sprinkled preliminary to ironing, each drop of water spreads by absorption and, displaces the acid pushing it out to the edge of the circle where it constitutes a ring of acid more concentrated than in the beginning. When the clothes are hung out to dry certain parts generally get the greatest exposure to air or wind and take up the greatest percentage of sulphur compounds, the parts which'rot most quickly after ironing. In the ironing operation, the high temperature carbonizes theacid-charged rings or spots; or, with the concentration of the acid, hydrolyzesthe cotton or removesthe water from the molecules thereof, which makes it brittle. These brittle spots are soluble in the alkali which is used in the next laundering operation. Consequently, in one or two subsequent operations the fabric is destroyed at the points of concentration of the acid. I

The conditions referred to, arise in most domestic laundering work where the clothes are hung in the atmosphere to dry and where the water is not sufliciently alkaline to neutralize the acid from the atmosphere. The same conditions occur in what are .called wet washes where the washed goods are delivered wet to the owner who then dries them in the atmosphere and irons them.

' And the same conditions may, occur to a greater or less extent-in other circumstances.

.I propose to remedy the trouble byaapplying to the f brie an agent capable of neutraland these are Application filed March 9, I925. Serial No. 14,341.

izing the acid or of altering its activity to a non-destructive character. This can be accomplished by introducing in suspension in the water used at or near the end of the washmg operation a suitable neutralizing agent. Example of such an agent are (1) chalk preferably in the pure preci tated form (CaCO (2) calcium borate (EaBOQ or (3) magnesium hydrate (MgO H o In the first ,example, the following reaction takes place when the fabric is moistened for ironing- CaCO, plus H sOgequals plus H,() The CaSO is a non-destructive compound which remains in theffabric until it is washed out in the next laundering. The CO goes caso,. p1us co,

ofi as a gas. The H O is evaporated.

With the third of the agents referred to above the following reaction takes place- MgO H plus H SO equals .MgSO plus The MgSO is a non-destructive salt which is washed out in the next laundering.

Similar reactions and results take place with other agents referred to above and with those cited below. Instead of the above-protecting agents we may use a solution of a soluble acetate, formate, fluoride or other salt which would cause the destructive acid to combine with the metallic end of the salt and liberate an acid which is non-destructive to the fabric. Such agents for example are (1) sodium acetate (NaC H O (2) potassium formate (NaF).

The agents of a third group can be used, being solutions of an alkali or salt having an alkaline reaction, such, for example, as (1) trisodium phosphate (Na PO (2) bicarbonate of sodium (NaHCO or (3) calcium hydrate (CaO H Instead of introducing-the agent directly into the wash. or rinse water there can be introduced agents which will combine in such water to form a protecting agent. For example, the fabric may be subjected first to asolution of a salt or base and afterwards'to anothersolution containing another salt or base which will form with the first a compound in the fabric which is relatively insoluble and of such nature as to neutralize the destructive acid ei her by changing its acid (KCHO or (3) sodium fluoride a dampened'and heated by the iron,

cium acetate (CaC H O and into the next rinse water, sodium carbonate (Na CO Or We may introduce into successive waters magnesium sulphate (MgSOQ' and ammonium hydrate (NH OH). Where two agents are used to combine and form the protecting agent desired, the two combining agents may be introduced in inverse order to that stated above. Or they may be introduced into earlier waters than the last two.

7 In fact, various agents vmay be introduced in various ways, the essential thing being to operate in such a way as to have some of the protecting ,agent remain in the goods after the have passed through all the washing an rinsing waters. v

In the generation of the protective. agent by these methods reaction in thefirst case will be as follows Ca 0 H 0 plus Na CO equals CaCO 3 2)2 plus 2NaC H Q 3 The CaCO thus produced is an insoluble salt. The NaO H O is the sodium acetate which serves as the protecting agent.

In the second case the reaction is as follows 'MgSO, plus QNILOH equals Mg(OH) 2 plus 4 2 4 In this case the Mg(OH') is the protective agent and the (NI-1,),SO is a harmless salt. The quantity of the protecting agent to be introduced is very slight, though it will depend to a great extent on the degree of acidity of the atmosphere; The protecting agent may be such as to combine with the acid chiefly in the air or chiefly when the fabric is or equally under both conditions.

Animal fabrics are not generally affected greatly by an acid atmosphere, though some. of the colors used therewith may be. Therefore the invention is particularly important in connection with cotton and other vegetable fabrics.

ity to a composition having a non-destructive character such as a salt or another acid which is not destructive. And while the agents used are designed particularly to protect the fabric against sulphuric acid, they will serve also to protect it against other destructive acids to which the fabric may be exposed.

ThoughI have described with great partioularity of detail certain embodiments of my invention, yet it is not to be understood therefrom that the invention is restricted to the particular embodiments disclosed. Various modifications may be made by those skilled in the art without de arture from the invention as defined in'the ollowing claims.

What I claimis 1. The method of laundering textile fab'- rics which consists in washing them as usual and thereafter applying thereto in rinse water a protective agent adapted to remain in the goods to prevent the destructive action of acid vapors and the formation of destructive acids in the fabrics.

2. The method of claim 1, the protective agent being adapted to transform any composition in. the fabric having a destructive acidity to a composition having a non-destructive character.

3. The method of claim 1, the protective agent being'adapted to prevent destructive action by sulphuric acid.

4. The method of claim 1, the protective agent being adapted to transform sulphuric acid compounds to compounds having a nondestructive character. J i

In witness whereof I have hereunto signed my name.

ROBERT PHAIR. 

